1. Field of the Invention
The present invention relates, in general, to supplying cool air in devices for refrigerators and, more particularly, to a supplying concentrated cool air device for capable of concentrically guiding cool air from a door duct to a hot area, newly loaded with foodstuffs, inside the fresh compartment of a refrigerator, thus more effectively cooling such a hot area.
2. Description of Related Art
The construction of a typical refrigerator is shown in FIG. 1. As shown in the drawing, a typical refrigerator comprises two compartments: a freezer compartment 2 and a fresh compartment 4. In order to supply cool air from an evaporator 5 to both compartments 2 and 4, a cool air supply device is provided in the refrigerator. That is, a portion of the cool air from the evaporator 5 is forcibly guided into the freezer compartment 2 by a blower 7. In order to guide the remaining part of the cool air from the evaporator 5 to the fresh compartment 4, a cool air duct 9 is arranged on the rear wall of the fresh compartment 4.
The amount of cool air for the fresh compartment 4 is controlled by a damper device (not shown) provided on the top portion of the duct 9. The damper device is operated in response to output signals from a plurality of temperature sensors (not shown) that are provided at several positions inside the fresh compartment 4.
The above temperature sensors are mounted on the rear and side walls of the fresh compartment 4 and sense the temperature in the compartment 4 prior to determining the opening degree of the damper device. The damper device thus controls the amount of cool air reaching the fresh compartment 4.
However, the above conventional cool air supply device is problematic due to the position of the cool air duct 9. That is, the above duct 9 is arranged on the rear wall of the fresh compartment 4, so that the cool air only flows from the rear of the fresh compartment 4 to the front of the fresh compartment 4. It is thus almost impossible to provide a sufficient amount of cool air to the area around the front portion of the fresh compartment 4 or the door baskets 8 of the fresh compartment 4. This negatively affects cooling change the foodstuffs in the front portion or in the door baskets 8. Thus, when repeatedly opening the door of the fresh compartment 4, atmospheric air rushes into the area around both the front portion and the door baskets 8 of the fresh compartment 4. The temperature around the front area of the fresh compartment 4 is therefore undesirably raised to a level higher than a preset point.
In order to overcome the above problem, a door duct may be arranged on the door of the fresh compartment 4 in addition to the above-mentioned cool air duct 9 provided on the rear wall of the compartment 4. An example of known refrigerators with such door ducts is disclosed in U.S. Pat. No. 5,584,191. In the refrigerator disclosed in the above U.S. patent, a door duct is formed on the door of the fresh compartment, thus allowing cool air from the evaporator to flow from the front to the rear in the fresh compartment. The refrigerator of the above U.S. patent also has a cool air duct on the rear wall of the fresh compartment in the same manner as described above. Therefore, the cool air also flows from the rear to the front in the fresh compartment. The above U.S. refrigerator somewhat uniformly cools the whole area in the fresh compartment in the three dimensions. The refrigerator also quickly cools the portion around the door baskets of the fresh compartment.
However, the above is designed for refrigerator is designed for continuously supplies a fixed amount of cool air to the fresh compartment, regardless of conditions of the compartment. That is, the amount of cool air provided to the fresh compartment is fixed regardless of the presence of foodstuffs inside the door baskets or a temperature difference between the areas in the fresh compartment. Therefore, the above refrigerator may fail to accomplish a designed cooling effect during its operation.
In a detailed description, new cooling load is added to the existing load in the fresh compartment which causes the temperature in the compartment to partially rise when some foodstuffs are newly stored in the front portion or door baskets of the fresh compartment. However, even in such a case, the cool air outlet passage of the door duct is not changed, but is fixed, so that the door duct fails to concentrically provide cool air to the hot portion of the compartment. This reduces the relatively cooling effect of the fresh compartment.